Shoe stuteneb and method obi maximo it



March 8 1932. E. LIONNE 1,848,732

SHOE STIFFENER METHOD OF'MAKING IT Filed Nov. 29, 1929 In 0627 for Patented Mar. 8, 1932 UNITED- STATES PATENT OFFICE Earns-r mourn, or N'Armnr, mssacnusn'rrs,

SHOE 'STJIFENER AND METHOD OF MAKING IT Application filed November 29, 1929. serial No. 410,354.

are bound. The sheet, specifically, is com posed of insoluble fibres such as textile fibres, wood fibres, and generally the usualpaper making fibres, and combined with soluble fibres such as pyroxyline, cellulose acetate, or other suitable cellulose esters. The sheet is made by inter-mixing the insoluble and soluble fibres in abeater and forming the sheet by customary paper making methods.

The stiffener made from such sheet had many advantages over prior stiifenersw I have found, however, that I can improve upon this type of stiffener. Pyroxyline and other fibres of this general type are harsh andbrittle and do not felt with themselves and with the insoluble paper making fibres'as'well 0 as is desired, so that the resulting sheet is fragile and is diflicult to handle without rupturing it when it is wet with solvent unless more care is given to the manufacture of the sheet than is desired. Furthermore, the dispersion of the soluble fibres in the sheet is not uniform and the sheet contains spotsjmade of bunched soluble fibres, which is not desirable.

I have found that I can obtain a better sheet and stiffener and one having more tightly felted fibres, greater mechanical strength, and uniformly dispersed soluble material, if instead of making thecsheet with a mixture of the soluble and insoluble fibres, I first'comminute the soluble fibres and destroy the fibrous nature thereof, as by pulping them into extremely fine particles, and thoroughly intermix the comminuted particles and the insoluble paper making fibres v and form a sheet from such mixture. This degree of fineness,

constitutes an object of the present invention.

In carrying out the invention, the pyrox yline or other soluble cellulose ester fibres alone are introduced, with the addition of water, into a paper beater and the beater is operated for so long as is necessary to comminute the fibres or to obtainthe requisite and, preferably, to pulp 1 them into extremely fine particles which may be amatter of hours. The beater should be operated long enough to destroy completely the fibrous structure andreduce the fibres to the condition of a finely ground pulp, the

degree of fineness of the comminuted material being at least such that the material can not felt with the insoluble fibres of the paper making stock. After the soluble material hasbeen comminuted, it is mixed with any usual or desired paper making fibres in the beater 7 and the beater is operated until a thorough dispersion of the comminuted soluble articles throughout the mass of paper ma 'ngstock is efiected, this dispersion being effected without difiiculty since the soluble particles are fine as compared with the size of the paper making fibres andhave approximately the same density as the fibres. ,The

'paper making fibres may be anything usual in the art as rag stock, wood fibres, and the like. The mixture of comminuted material and paper stock is then flowed from the stuff box of the usual paper making machine onto the paper making wire in a F ourdrinier or cylinder machine, or the paper can be laid in any desired manner. The insoluble or paper makingfibres on. the wire become felted together in the usual manner. The commi nuted soluble material occupies the voids between the insoluble fibres. The sheet thus formed can be dried and calender'ed as is usual in paper -ma king. Preferably, however, the temperature of drying should not be so great as to decompose the particlesof comminuted material. The calendering should be light enough to provide a paper sheet which is porous so that it can be penetrated rapidly by'a suitable solvent for the comminuted material.

' Since the comminuted soluble material ocmo cupies the voids-between the pa r making fibres, these fibres can felt toget er without ed material is uniformly dispersed through out the sheet and does not collect in isolated ots, as with the sheet formed-with soluble res, and the material occupies the voids between the insoluble felted bres and it is retained therein by the interlacin of such fibres. When the sheet, or a sti ener cut therefrom, is treated with a. solvent for the Y eomminuted material, which solvent canbe form, whichiespecially when assisted well known solvent as acetone, wood alcoand the like,'the eomminuted particles are converted to a colloidal or gelatinous b the pressure of asting the shoe withastitlener therein, spreads throughout the sti-fiener and in between and over "the insoluble fibres there- Q of and unites when the solvent has evaporated to form a stifl uniform film which is integral and is dispersed uniformly throughout the body of the stifi'ener, and which encloses and bonds together the insoluble fibres and retains the stiffener inthe shape imparted to 7 it lliplthe last.

e proportion of eomminuted material to insoluble fibres can be variedwithin wide hmits, For a relatively stifl stiifener, equal 1 I j parts of eomminuted material and insoluble fibres can be used. Where a stifiener having less stiffness is satisfactory, the amount of eomminuted soluble material can be reduced.

For convenience and economy, I employ a material consisting of ieomminuted nitrocellulose fibre but not do not necessarily limit myself to this material as other esters of cellulose such as cellulose acetate, butyl ccl lulose and the like, can be employed, or other material formed from film-forming fibres which are soluble inv a suitable solvent'a nd,

preferably, are insoluble in water, so that the stifi'ener W111 not lose its'shape when the shoe inwhich it is built becomes wet.

I have found that the use of eomminuted material prepared from soluble fibres has a number 0 a vantagesover a soluble material which exists in another form, as celluloid in a anular form. I

y eomminuted material has approximately the density of the usual paper making fibres so that it can be dispersed uniformly throughout the paper stock and kept in sus pension therein and thus can produce-a uniform paper sheet. By reason of its. ability to remain insuspension, but a small amount 7 of the material is lost through the paper making wire. A granular celluloid is materially heavier than the paper making fibres and does not readily remain in suspension in and in dispersed condition throughout the paper stock so that the resulting sheet is not readil made uniform and; a considerable quantlty of the granules is lost through the paper making w1re. My eomminuted material'hydrates to some, degree during the heatmg process so that, in the finished sheet, the 7 particles adhere together and to the adj a-' cent fibres, thereby preventing loss of niaterial through the wire and making a strong er sheet than agranular celluloid which does not hydrate so that its particles have no affinity for themselves or for the paper making fibres. Y r

The dry sheet made from my material does not lose eomminuted material when the sheet is wrapped, while a sheet having granular celluloid will have its granular particles shaken out. p

1 In the drawings, Fig. 1 is a plan view of a shoe stiflen'er embodying the invention and Fig. 2 is an enlarged section of the material composing the-stiffener, wherein 10 represents the insoluble interlaced or felted fibres and 1 2 the eomminuted soluble particles made from soluble fibres and which occupy the voids between the felted insoluble fibres but are not interlaced therewith.

I claim: 1. A shoe stifl'ener containing interlaced insoluble fibres and eomminuted partieles'of soluble ,fibrous material contained in voids between the insoluble fibres. 1

2'. A paper sheet composed of felted insoluble fibres and eomminuted partilesof soluble fibrous material contained in the voids between the felted fibres.

3. A shoe stiffener containing interlaced insoluble fibres and eomminuted particles of a fibrous cellulose ester contained in the voids between the insolublefibres.

4'. A shoe stifi'ener containing interlaced insoluble fibres and eomminuted particles of pyroxylinefibres contained in the voids betweentheinsoluble fibres.

5. A paper sheet composed of felted insoluble fibres and eomminuted particles of a fibrous cellulose ester contained in the voids,

the

between the felted fibres.

6. A paper sheet composed of felted insoluble fibres and eomminuted particles of pyroxyline fibres contained in the voids between the felted fibres. v I 7 I 7. A paper sheet composed of felted insoluble fibres and eomminuted particles of a soluble'hydratable fibrous material contained in the voids between the felted fibres.

'8. A paper sheet composedof felted insolble fibresandeomminuted particles of a soluble fibrous material contained in the voids between and free from felting relation with the felted fibres.

9. A paper sheet composed of felted inincapable of felting with the felted inso fibres.

10. A aper sheet composed of felted insoluble fibres and comminuted particles of soluble fibrous material contained in the voids between the felted fibres, the particles having such a degree of fineness that the are soluble fi ers and comminuted particles of soluble fibrous material contained in the voids between the felted fibres, the particles having such a degree of fineness that they are incapable of felting with the felted insoluble fibres, and having approximately the density of the insoluble fibres.

11. A shoe stifli'ener containing felted insoluble fibres and unfelted pyroxline.

12. A paper sheet composed of felted insoluble fibres and comminuted particles of soluble fibrousmaterial contained in the voids betweenthe felted fibres, the soluble particles having a proximately the density of the insoluble fi res.

. 13. The method of making a paper sheet I which consists in beating soluble fibres in a paper beater until the fibres are comminuted, mixin the comminuted fibrous material with insolu le paper making fibres, and forming ing particles of a soluble fibrous material conname to this specification.

a sheet from such mixture. g 14. The method of making a paper sheet which consists in forming a'paper sheet froni a mixture of insoluble paper making fibres and soluble fibres which have been comminuted to such a degree of fineness that they cannot felt with the paper making fibres.

' 15. A shoe stifiener containing interlaced insoluble fibres and comminuted film form- ERNEST LIONNE.

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